Perfluoroalkyl acids (PFAAs) are persistent, ubiquitous environmental contaminants and their long-chain representatives are bioaccumulative. The phase-out of these compounds (e.g. PFOA and PFOS) shifted the production to alternatives. However, little is known about the bioaccumulative behaviour of the alternatives, which are still highly fluorinated. PFAAs are predominantly detected in blood, where they bind to the transport protein serum albumin. This sorption can be described by the albumin/water partition coefficient. It is unclear whether the partition coefficients of the alternatives are lower than or in the same range as those of classical PFAAs. We determined albumin/water partition coefficients for seven perfluoroalkyl carboxylates, three perfluoroalkane sulfonates and four alternatives by dialysis experiments in a physiologically representative system. Quantification was done by LC-MS/MS and a mass balance approach. Logarithmic albumin/water partition coefficients for PFAAs range from 2.8 to 4.8 [L_water kg_albumin⁻¹] and increase with increasing chain length. Perfluorinated sulfonates sorb more strongly than their carboxylate counterparts. The albumin/water partition coefficients for the alternatives (HFPO-DA, DONA, 9Cl-PF3ONS and PFECHS) are in the same range as for classical PFAAs. Structural modifications such as the introduction of ether groups into the chain do not reduce sorption to albumin, whereas the chlorine atom in 9Cl-PF3ONS seems to even increase the sorption to albumin. We further investigated whether the sorption strength could be affected in the presence of medium- or long-chain fatty acids. Binding competition between medium-chain fatty acids and PFAAs appeared to be possible. However, the presence of physiologically more relevant long-chain fatty acids should not alter the albumin/water partition coefficients of PFAAs.

中文翻译：

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与十种经典全氟烷基酸相比，牛血清白蛋白（BSA）和水之间四种全氟烷基酸替代物的分配系数。

全氟烷基酸（PFAA）是持久存在的普遍环境污染物，其长链代表具有生物蓄积性。这些化合物的淘汰（例如PFOA和PFOS）将生产转移到了替代品上。但是，对于仍然高度氟化的替代物的生物蓄积性知之甚少。PFAA主要在血液中检测到，并与转运蛋白血清白蛋白结合。这种吸附可以用白蛋白/水分配系数来描述。尚不清楚替代方案的分配系数是否低于或高于经典PFAA的分配系数。我们通过在生理学上具有代表性的系统中的透析实验，确定了七个全氟烷基羧酸盐，三个全氟烷磺酸盐和四个替代物的白蛋白/水分配系数。通过LC-MS / MS和质量平衡方法进行定量。PFAA的对数白蛋白/水分配系数范围为2.8至4.8 [L_水千克_白蛋白^-1并随着链长的增加而增加。全氟化磺酸盐比其羧酸盐对应物吸收更强。替代品（HFPO-DA，DONA，9Cl-PF3ONS和PFECHS）的白蛋白/水分配系数与经典PFAA的范围相同。结构上的修饰（例如将醚基引入链中）不会降低对白蛋白的吸附，而9Cl-PF3ONS中的氯原子似乎甚至会增加对白蛋白的吸附。我们进一步研究了在中链或长链脂肪酸的存在下吸附强度是否会受到影响。中链脂肪酸和PFAA之间的结合竞争似乎是可能的。但是，生理上更相关的长链脂肪酸的存在不应改变PFAA的白蛋白/水分配系数。